RV Repair: electrical short/turn signals, turn signal switch, neutral safety switch

Question
have a 1997 Chevrolet 3500, diesel truck that overheated last Sept. Caught a glow plug wire on fire (was supposed to be repaired, but wasn't). Turn signals keep blowing fuses, was intermittently but now , much more often. Had it to 3 dealers and no one can find the problem. It blows a fuse everytime you put it in park now (used to only do that occasionally). You can keep it from blowing the fuse by putting truck in neutral, pulling the fuse then putting it in park. Need to keep fuse out until you put in in neutral again, when you start it up. They have replaced the neutral/safety switch (on the transmission) tested the turn signal switch and various others but no one can seem to find the problem. Can you help ?

Answer
Carol,
     Since you said you can put it in neutral and pull the fuse and then put it in park it doesn't sound like the neutral switch was the problem.  My guess is that the back-up light circuit is the problem as you pass from neutral through reverse and on to park.  I would start by eliminating the power to the back-up lights to see if that stopped the problem.  I hope this helps, but this is a tough one to try to solve without being able to go through and test it.

Darren